


imperio

by Anonymous



Category: Harry Potter - J. K. Rowling
Genre: Dubious Consent, F/F, Light Dom/sub, Orgasm Delay/Denial, Sibling Incest, Vaginal Fingering
Language: English
Status: Completed
Published: 2020-09-01
Updated: 2020-09-01
Packaged: 2021-03-06 14:54:27
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,357
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26240704
Author URL: https://archiveofourown.org/
Summary: Cissy wanted this and God, she wanted Cissy.
Relationships: Bellatrix Black Lestrange/Narcissa Black Malfoy
Comments: 10
Kudos: 50
Collections: Anonymous





	imperio

**Author's Note:**

  * Inspired by [Amphierotic Bloodlines](https://archiveofourown.org/works/4028710) by [SapphireSmoke](https://archiveofourown.org/users/SapphireSmoke/pseuds/SapphireSmoke). 



"Bella, this is an unforgivable!" Narcissa squealed. They were in the bedroom, but Bellatrix still felt her hackles rise at the squeal as if someone might overhear. The house was quiet, except for the bloody house-elf, but anyone could suddenly pop in.

"Jesus Cissy, get over yourself. It was only outlawed two-hundred years ago. Look, just aim, say the word and then––"

"I could go to Azkaban for this!"

Bellatrix paused, raising her eyebrow. "So? It's not like anyone's going to know."

Narcissa looked unsure, staring down at her wand as if the curse had already been cast. "Can't they find out?"

"They can only check by getting your wand to cast its last spell, but if you've cast something else, they're never going to know. God, didn't they teach you anything at school?"

Narcissa opened her mouth, her lips shaping into a cute pink 'o' shape she often did when caught between what she wanted to do and what was practical. If she wasn't being so annoying right now, Bellatrix might have kissed her and then fucked her against the wall or something.

"Look, if you don't do it, I'm just going to get someone else, so just––" she gestured, pointing to Narcissa's wand. "Alright?"

"Bella." It came out as a whine, high and jarring in her ear.

"For fuck's sake, Cissy." She ran a hand through her hair, trying to bite back the growing venom that seemed to burn in her lungs as her annoyance grew. They'd been back and forth with this for over ten minutes, and she needed to learn one way or another. "We'll only do it the once to see if I can break it if. I can, then whatever, we'll forget about it, okay?"

Narcissa's shoulders seemed to rise, the tension drawing across her body before she bit her lip. Bellatrix could see her sister's thoughts ticking away, as she weighed the pros and cons in her mind. In the end, she knew she would agree if only to prevent her from going to someone else. "Okay," she said, her shoulders sagging. "Okay. What do I need to do?"

"Just point your wand at me, think about wanting to dominate and then just say the word imperio. It's easy, even your fucking fiancé could do it." She didn't tell her that he already could because that detail wasn't necessary and only likely to distract her.

"Okay. Um, here we go. I-imp––"

"Jesus fuck, Cissy, spit it out."

"Just give me a moment!" Narcissa said, her hand shaking as she held the wand outright. It wasn't even that difficult of a spell to master. God, Lucius had mastered it on the third attempt, and yet here was her little sister, shaking like she was trying to cast crucio on her instead. Of all the alleged unforgivables, this spell was the easiest to use and master. "Imperio." 

The spell splattered against her shoulder and Bella closed her eyes, anticipating the curse. For a second, she felt the familiar shiver wash down her spine, and then the feeling left.

Bellatrix snapped her eyes open, glaring at her sister. "Pathetic."

"Bella! Come on, I tried."

"Not fucking hard enough! You have to mean it. Point it and mean it. You always wanted control, right? That's why you stopped eating, well here it fucking is. Here's your control, so grow a pair and just say the fucking word!"

Her sister's face hardened, "Imperio."

Bellatrix felt the spell hit, this time with more force.

She'd been under it once, and only once.

The Dark Lord had cast it, showing her what the mudbloods felt. It'd been so easy, like receding far into the back of her mind and letting him puppet her into torturing Rodolphus, just to show her how easy someone could control her. Manipulate her into doing another's will, and then he'd done the same to Goyle, and that idiot had managed to almost resist, it'd pissed her off.

And it terrified her.

Fucking hell. Torturing Rod was easy, she didn't need the Dark Lord's influence to do that, but the idea that she wasn't strong enough to shake off his will if he made her do it to someone she cared about wasn't a warm fuzzy thought.

When Cissy cast the spell, Bellatrix felt the effects wash over her. She felt the warmth spill through her chest as if a heating charm had been cast. The thing in her mind seemed to draw back, receding until it was barely present, tiny and small.

And then it disappeared altogether.

She wasn't her sister's marionette. There were no strings. But when she looked up at her sister, watched her tuck the blonde behind her ear, tilting her head as if she wasn't sure the spell had worked, Bella thought their mother must have fucked a veela.

Cissy was so beautiful when she bit on her lip like that, her brow pressing together.

God, she'd do anything for her.

"Um, now what?"

She should answer the question. But…but she didn't know the answer. What did Narcissa want from her? The question seemed to curl inside of her, an urgency to answer but a void of unknowing filling her. 

"Oh, I guess you can't …answered. Um." Narcissa looked around the room, drawing her eyes from the bed to the window to the floor.

Bellatrix felt the urgency leave her, the question didn't need to be answered now, and her sister was darting her eyes around the room, inspecting everything for an idea. She looked sweet, holding her wand in one hand as she bit her bottom lip. 

Bellatrix felt herself stepping forward, wanting to kiss her.

"Get on your knees."

Bellatrix paused. Her chest ached at the command, she didn't want to get on her knees. That wasn't her place. 

Only filthy…

No.

Cissy wanted this. 

Her knees buckled, fighting her, but it felt right. Cissy wanted this and God, she wanted Cissy. 

Bellatrix knelt, like a knight before their princess, and then felt her other leg slide into place, as she sat down on her knees before her Cissy, hands hanging at her sides as she looked up at her sister. 

Narcissa looked lovely as pink began spilling over her cheeks and across the crest of her nose. It made her blonde hair looker paler, and her eyes all the brighter as excitement grew in them. 

Bellatrix felt her own excitement press between her thighs and tighten in her chest. Narcissa was pleased, so she was pleased.

Her sister rocked on her feet, looking at her as if a great idea had punctuated her thoughts. "Tell me, you love me," Narcissa asked, her voice strained as if she was trying to contain her excitement

"I love you."

"Tell me, you want me."

"I want you."

"Tell me, you're going to fuck me."

"I'm going to fuck you." 

Narcissa's face fell, "See, you don't mean it. Bella, this feels wrong. I don't want to do this." 

Bellatrix's chest tighten. It was like a string snapping, and suddenly the enchantment faded, and she could feel everything again. That horrible, nasty acidic feeling was creeping through her chest, and she could sense it crawling out from the recesses of her mind like a fucking parasite. 

"Fuck!" she snapped, pushing up onto her feet as she ran forward and grabbing Narcissa, slamming her against the wall, "Fucking hell! Why would you stop? Why?" Her sister drew her eyes away, shaking as Bellatrix clutched tighter, "Damn it, Cissy. What the fuck?"

Narcissa head lulled, her eyes drawing up at her. "Because it wasn't you, Bella. I don't want to do this if it's not you."

Bellatrix felt her nails dig into her sister's arm, the anger growing before she pushed away from her and turned around, going to leave as she tossed over her shoulder, "Forget it. If you're too much of a pussy to do a little spell, then I'll go get someone else who has big enough balls to actually do it." 

"No! No, no, I'll do it. I'll do it," Cissy said, her fingers clawing at her arm to draw her back. "Please, Bella. Please don't go. I'll do it."

Bellatrix turned, looking over her shoulder. The disgusted wavered inside of her as she felt the other part of her sink through. "Can you even manage it?" she hissed.

"I can. I promise."

Bellatrix felt her world shrink, a clawing sensation inside of her as she turned and stared at Cissy, watching her sister's eyes blink back the growing tears. "No, I think you need a little demonstration."

Narcissa stared at her, blinking before she scrambled backwards, lifting her wand hand up to defend against her.

But Bellatrix was faster, the spell slipping from her wand as easy as a first-year charm. Her sister slackened, dropping against the wall before she stared up at her. There was a tightness in the eyes before it slid it away. Bellatrix smiled, looking at her very own puppet. 

"Come here, love," she said, summoning her sister forward. Narcissa stepped forward until she was standing directly in front of her, her chest rising and falling in slow breaths. There was a panic there, deep inside of Narcissa's chest, but Bellatrix pushed at the imperio curse, letting it spin around her like a spider's web until there was nothing left. "Now, stand still like a good girl."

Then Narcissa was standing still, like an obedient little sister. Back straight, head forward, just like dearly departed Mother taught them.

And wasn't it time that Narcissa was an obedient little sister? After all, Bellatrix had opened up her house and home to Cissy, she committed parricide for her, murdered that blackmailing cunt of a girl, and all she got was an ungrateful brat who couldn't handle a simple spell because it made her feel icky. 

But the question was, what to do with her?

She tilted her head, drawing her eyes over her sister's body. She took a turn in a circle, watching her sister's skin prick as she touched over her shoulder, down to to the where clavicle remained bare from any cloth to the very edge of the dress, cutting over her cleavage. "See the trick, Cissy is that you need to be specific." She touched her forefinger to Narcissa's chin, tilting her head up. "Right there, in this delightful spell, everything feels safe and warm, and anything I say sounds so very right, doesn't it? Nod your head for me, love."

Narcissa nodded her head once under the instruction. She looked so sweet, like a perfect porcelain doll. Bellatrix could eat her up if she wanted to.

"I could make you do anything," she told her, coming around behind her. She slid her hands down Narcissa's arms to her forearms, before grabbing at her wrists as she set her chin on her shoulder. "I could make you fuck yourself. Would you like that? Nod if you agree." Narcissa nodded once. "Such a good girl, for me."

Bellatrix plucked the wand from her sister's hand and tossed it to the bed before she wrapped her arms around Narcissa's waist. Her sister remained still, waiting for her next command, but Bellatrix didn't know if she did want to command her. It was fun with muggles and mudbloods, making them grovel and beg and do all sorts of things to each other, but Cissy would be quite unhappy once the spell ended and honestly, that was more bother than it was worth.

She let go of her sister and stepped back. "Turn around and smile at me."

Narcissa turned around to face her. Her smile was bright, but it didn't quite reach the eyes. It never did, no matter how specific she was with her toys. 

"Get undressed."

Narcissa began pulling at her dress, and as she did, Bellatrix lifted the curse, watching as her sister froze, arms lifting above her head to remove the robes before she stopped and looked at Bellatrix.

"Bella, what the fuck!"

Bellatrix tilted her head, watching the pink bloom across her sister's chest. "Now you see," she said.

"If you think I'm just going to––"

"I do," Bellatrix said, picking up Narcissa's wand from the bed and holding it out for her.

"You really are mad. How can you even think I would ever do something like that to you, "she snapped, reaching out for her wand. Bellatrix tugged it away as her fingers nearly wrapped around it. "Just give me back my damn wand!"

"You're going to do it because you now understand why I need to fight it."

Narcissa paused, her lips parting as her thoughts seemed to stutter. "Fight it? Why would you need to fight it?"

"Oh, grow up, Cissy. You think other wizards are above using it to get their way?"

Narcissa's brow pressed together, fear growing in her eyes. "Who' s––?"

"Doesn't matter. I need you to use it on me so I can break out of it. Can you do that, or are you going to be a baby about it, again?"

Narcissa stared at her, eyes flickering between Bellatrix's own before her face softened. "You really want this?"

"Did I fucking stutter?"

Narcissa rolled her eyes, crossing her arms underneath her chest. "Fine, whatever. But can't we use a safe word, discuss boundaries or something?"

"There's no fucking safe word or boundaries with this spell, that's the whole point. You just need to use it until I break out of it. Can you do that?"

"I––Yes."

"Can you?"

"I said yes, God damn it, Bella just give me back my fucking wand." 

Bellatrix reached out her hand, holding it out to sister and watched as she quickly snatched it back as if she didn't trust her to pass it back to her.

"What do I make you do?" she asked, sounding insecure.

Bellatrix rolled her eyes. "Whatever you want," she drawled. "Now, for fuck's sake can you just point your want and fucking––"

"Imperio," Narcissa said before she could finish. There was a soft, good girl that echoed through Bellatrix's thoughts. And then a sense of darkness, all-encompassing before it receded far into the depths of her mind.

The ache in her chest eased, and a sense of warmth filled her, spilling down her spine. 

It was so easy to lose yourself in it, to have the world shrink until only one person existed, have their words dripping into your ear, warming you from the head to tail. 

"Okay," Narcissa said. "Well, thankfully, I have an idea. So just…get undressed and lie on the bed while I get ready."

* * *

Narcissa had bound her arms together and spread her legs apart, tying them to either post at the end of the bed. Even from the depths of her mind, she could feel the excitement growing warm in her lower belly as Narcissa slipped between her legs, looking so very lovely in her choice of lacey lingerie.

The bedroom door was shut, her sister assured, sealed and spells had been cast to keep any unwanted visitor from hearing them. 

And then her sister had dragged her fingers over her body, nails bluntly drawing from chest to hips to thighs until her skin pricked with excitement and arousal grew between her legs. 

Narcissa smiled at her, her eyes shining wickedly as she drew her fingers over Bellatrix's slit with just her forefinger, watching her body react. With two fingers, she slid upwards, and Bellatrix sighed, feeling her cunt throb, aching for Narcissa's fingers to slide inside of her.

"I want you," Narcissa said, looking up at her with a bright grin, before she continued, "to keep absolutely silent, no matter what I do to you. And you must keep as still as possible, I mean, you can breathe, but nothing else. Got it?"

Bellatrix felt her body lock as if she'd been stunned by a duelling hex. Her sister only grinned wider as she drew her fingers across her slit, teasing as if to test Bella's limits.

Her throat seemed to swell, a sound wanting to pull at her sister began drawing her entrance before slipping away. "Mm, you're already so wet, Bella. Imagine what you could be doing if could ride my hand," she said, using more force to slip back and forth, sliding over clit and down to where Bellatrix wanted those fingers to be.

Obedient in the spell, Bellatrix did imagine: she thought about Narcissa's fingers inside of her, of thrusting her hips over those fingers and rubbing against Narcissa's thumb. She thought about riding her sister's face and how good it would feel to grind against her mouth and make her use that tongue until Bellatrix was satisfied.

And as she thought of it, she felt herself clenching involuntarily, squeezing around the absence of her sister's hand as her sister continued to draw over the labia with gentle fingers, teasing the entrance of her cunt.

Bellatrix tried to snap and tell her to just fuck her, but the feeling rose and subsided, softening as Narcissa straddled her hips, her hand drawing away as she leant down to kiss her. 

It was as if her world focused on Narcissa, and all she could think was to be good and obey her mistress. 

Narcissa's lips were soft, the kiss gentle like before. She wanted to kiss her back, to deepen the kiss and suck at Narcissa's bottom lip, but her body remained impassive, following the order. 

It felt right to follow the order, to be good and make Narcissa happy, and she could feel Narcissa's growing happiness on her belly as her sister's rubbed against her.

Her mind grew hazy and pleased, staring out as she felt her sister's mouth kiss down her cheek, to her throat and begin sucking against her pulse point as a hand grabbed her breast and squeezed. Narcissa adjusted her grip, pinching the nipple between two fingers before she began biting at Bellatrix's throat, sucking it hard enough to leave marks. The sharpness seemed like a direct like to her cunt, pulsating as she felt her eyes flutter. 

Bellatrix could feel the moan building in her throat, feel the vocal cords trying to make the sound, but all she did was breathe in, and then exhale out a long, tight breath as her heart thudded in her chest. Already, she could feel the cold air on cunt, making the growing throb prominent until all she could think about was how much she wanted Narcissa inside of her.

"Oh, I can feel that you want to Bella. But you can't, you have to be quiet and still." And then Narcissa was sucking on her throat again and sliding two fingers inside of her, just like she wanted.

No.

It wasn't enough. Bellatrix drew in a breath and held it, feeling it tighten and expand in her chest as Narcissa began sliding inside of her with only two fingers.

Bellatrix exhaled, looking up at the ceiling as she felt her sister's thumb drawing over her clit. It was enough to cause a tightening in her stomach, a growing restlessness building inside of her. Narcissa was purposely teasing, her mouth drawing across her shoulder as teeth bluntly pulled over the skin. She needed to break it, she needed to get out, she needed to…

"Be good, Bella," Narcissa said her words murmuring over her skin. She felt the spell buzz down her spine, warming her. The tightness pulled in her belly, her muscles clenched twice and then easing as Narcissa drew out and back, coaxing the entrance as her thumb slid over her clit again, rubbing in tempo with the slow thrusts in and out of her. 

It was too slow, there wasn't enough, she couldn't clench tight enough, she couldn't ask or beg or plead or––

The fingers drew away, and then Narcissa's mouth was drawing down her sternum, her body sliding down as the damp lace of her underwear slid over her body. 

Bellatrix could feel Narcissa's mouth slipping down her belly, over her mound and kissing down, across her folds until Bellatrix could feel the breath of Narcissa's laughter drawing across her exposed cunt.

"You really want it, don't you?" Narcissa asked, but she couldn't answer.

Because of the fucking spell.

Fuck.

"You know what you need to do," Narcissa sung before the very tip of her tongue slid from bottom to top, and then again, firmer, drawing between the folds, but not quite touching where Bellatrix needed her.

She could feel the need to be touched burning her, the impassiveness of her body growing harder and harder. And then it fell, and she found herself waiting between each moment of Narcissa's touch, becoming like a marble statue. 

"Or maybe you like this," Narcissa said before she swirled her tongue across the clit in a featherlight pressure that was maddening. She was growing closer to a precipice of something, and by God, if she came from such bullshit featherlight touch, Narcissa would pay.

Her sister kissed her, the tongue pressing against her entrance before flicking up and Bellatrix felt her thigh quiver, her forearms clench in their bindings. She could feel a need to press against the command, a demand to push.

But as the demand rose, it fell, and she grew impassive, a softness settling like a fog in her mind that she needed to be obedient, that Narcissa was right, she needed to be good, and still and quiet. Because she wanted to––

The tongue slid firmly and then disappeared, leaving only the promise of what it could do, and Bellatrix felt the spell grow taught. It seemed to electrify down her spine and up to the base of her skull as Narcissa's mouth worked against her cunt, drawing embarrassing amounts of wetness to spilling down her cunt, onto the bedsheets. 

Bellatrix felt the orgasm tugging at her, teetering closer, but Narcissa pulled away. 

No, she needed…

Kisses were being laid over her thighs as they shook in anticipation of what could have been. "You're so close, aren't you?" Narcissa asked as she slid one finger inside of her, rubbing at a particular spot that was making her want to dig her heels into the mattress and tug at the bindings, but the impassiveness held taught.

And then it snapped, and Bellatrix felt her heels dig, her muscles clench as wrapped her hands around the bindings that went above her head. "Fuck!" she screamed, and sister laughed as she began rutting against her hand like an animal heat, "Fuck, Cissy, just fucking fuck me!"

"As you wish," Narcissa said, as her mouth moved to her clit as she slid three fingers inside of her like a good girl and fucked her until the first orgasm came and went, permeating through her, but not enough. She still felt alive and tingling and God, she needed more, fucking, please. 

And she realised she was saying the words out loud, almost crying as she begged, "Don't stop. God, Cissy, don't––please!, "she keened, feeling the pressure rise again, quicker this time as Narcissa sucked on her clit, as her fingers spread inside of her, filling her as she clenched around them until she was sobbing through an orgasm that rocked through, washing relief up and down her body until her muscles sagged in relief. 

Bellatrix exhaled, feeling sparks of magic pricked at her skin, sparking over her nerves with the remnants of the orgasm clenching inside of her.

Narcissa waved her wand, and the bindings disappeared before she crawled up the bed and slid next to her, placing a hand onto her stomach as if she wasn't sure. "Bella?" she asked softly, asking a quiet question.

Bellatrix opened her eyes, peering out at her sister as she gave a soft exhale. "That was…exactly what I wanted," she said. "You did the right thing."

"You're not mad?"

"No, I'm not mad." 

Narcissa smiled, pushing up to press a kiss to her lips. This time, Bellatrix was able to kiss her back with languid ease, still in a post-fucking haze until they both dropped away, staring at each other. 

Bellatrix reached out, tucking a strand of hair behind Narcissa's ear. "Would you be up for doing it again?" Bellatrix asked.

"Not if you ever put me under that curse," Narcissa said, her eyes turning cold as she glared at her. "That was horrible, and the things you said were awful."

Bellatrix rolled her eyes. It wasn't like she actually made her do anything. "Admit it, you liked having absolute control."

"I––"

"It's okay, I like it too."

Narcissa went quiet, seeming to be troubled by her words, but whatever she wanted to say didn't come out as she ended up snuggling against her side. She was quiet but tense. And when the tension grew unbearable, she lifted up her head and asked, "Why did you want to learn to break out of it. And don't tell me it's because a wizard tried to use it on you. After all, you'd just murder him."

"The Dark Lord used it to make me torture Rodolphus," Bellatrix said, feeling the words come out distant to her own thoughts. She hadn't felt bad when she'd done it, she still didn't feel bad about it, but the context of the situation was wrong. The Dark Lord could use it against her to hurt Cissy, and she couldn't allow that to happen, not ever. 

"Bella, you––"

"I don't want to hear it, Cissy. Just…help me learn to break it, okay? He won't be angry, he'll be pleased, and then I'll never have to do that again."

Narcissa was quiet before she nodded against her. "Okay," she agreed. "I'll help you."

"Good." Bellatrix turned, kissing the top of her sister's head. "We should get cleaned up before Rod comes home anyway."

Narcissa nodded but didn't move as she wrapped her arm tighter around Bella. "Just a few more moments."

Bellatrix softened, falling back on the bed. "Fine. A few more minutes then."


End file.
